title: Natural killer cell activity and frequency of killer cell immunoglobulin-like receptors in children with different forms of juvenile idiopathic arthritis.
abstract: BACKGROUND
  Juvenile idiopathic arthritis (JIA) has three major onset types with widely varying clinical features: systemic, polyarticular and pauciarticular. We assessed natural killer (NK) cell function and killer cell immunoglobulin-like receptor (KIR) genotypes in patients with different JIA subtypes.
  
  
  METHODS
  Peripheral blood samples from 72 children with active JIA (systemic, 25; polyarticular, 24; pauciarticular, 23) and 25 controls were used for flow cytometric assessments of NK cell count, cytotoxicity, perforin, granzyme B, interferon (IFN)-γ and tumour necrosis factor (TNF)-α. Samples from 220 children with JIA (systemic, 84; polyarticular, 72; pauciarticular, 64) and 150 controls were used for KIR2DS2, KIR2DS4, KIR3DS1, KIR2DL1, KIR2DL2, KIR2DL3 and KIR3DL1 typing by polymerase chain reaction with sequence-specific oligonucleotide probes.
  
  
  RESULTS
  Compared with the controls, the patients with systemic JIA showed lower NK cell counts, cytotoxicity and perforin and granzyme B expression (p < 0.05), while the patients with pauci- and polyarticular JIA showed higher perforin and granzyme B expression (p < 0.05). NK cells produced higher level of TNF-α while lower level of IFN-γ in the pauci- and polyarticular JIA groups than in the systemic JIA group (p < 0.05). No significant differences in KIR gene frequencies were found between the JIA subgroups and healthy controls, except for the positive frequency and locus frequency of KIR2DS4, which were lower in the systemic JIA group.
  
  
  CONCLUSIONS
  Compared with poly- and pauciarticular JIA, systemic JIA is associated with decreased NK cell function, more IFN-γ and less TNF-α secretion of NK cell and lower KIR2DS4 frequency.
authors.affiliation: Ministry of Education Key Laboratory of Child Development and Disorders, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorders, Children's Hospital of Chongqing Medical University, Chongqing, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Zhou
authors.forename: Xuemei
authors.initials: X
authors.lastname: Tang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Ding
authors.forename: Yunfei
authors.initials: Y
authors.lastname: An
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D001171:Arthritis, Juvenile / Q000145:classification / Q000276:immunology*; D002469:Cell Separation; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003602:Cytotoxicity, Immunologic; D005260:Female; D005434:Flow Cytometry; D005838:Genotype; D053804:Granzymes / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology*; D018655:Lymphocyte Count; D008297:Male; D054353:Perforin / Q000378:metabolism; D054340:Receptors, KIR / Q000235:genetics / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D054340:Receptors, KIR; D014409:Tumor Necrosis Factor-alpha; D054353:Perforin; D007371:Interferon-gamma; D053804:Granzymes
keywords: cytokine; cytotoxicity; juvenile idiopathic arthritis; killer cell immunoglobulin-like receptor; natural killer cell